I'm looking to meet 450whp

My motor stock 5.0 302 block. With crane cam roller rockers(last owner installed it)
The engine has about 10k since stock rebuild.

Car has headers and full exhaust which will be modified when turbo is installed.

Instake is wieand 7515 with holler 4150 650cfm modified for blow through.

Turbo is
74mm garret t6 .91/.90 a/r

Looking to boost max 10 psi or lower if goal is achive.

Will my setup make it?


I was also offered to trade for a Paxton sn92 kit just for my turbo.
Will the paxton hiit 450whp? I'm almost possitive I will need heads right?

 

We had a f-cam and a holley systemax intake on a stock 100k engine. With a 62mm turbo, made 483rwhp.

john

 

What psi? I know the turbo can make big power but the # of boost is limited bc of the stock motor.

 

15psi

 

The T-6 Garret won't even be puffing that hard at all to hit 450RWHP.

That turbo can support some pretty big numbers.

 

I figured that I would need about 8-10 psi?

Ya my final goal is 800whp with this turbo. But that will be later when I get a crate motor. I figure 450whp is good for now. Atleast I will have it running right before I upgrade the motor.


Any thoughts on the sn92 supercharger?

 

Why does the amount of psi matter? The only thing that matter is to keep under a certain hp. It it doesn't matter how much boost it takes to get there. Boost psi is a measure of restriction.

 

It does when your running it on a stock motor.

While I understand what your saying but I simply can't just run x amount of pressure without considering the risk.
Shoot if a stock 302 can handle 800whp I'll boost it. But from what I have read 500whp is the safety margin. So I'm staying below that.


I was simple asking.if I could meet my goal at that pressure.
This will be a daily driven car aswell so reliability is a plus.

 

No it doesn't matter. Boost is not what splits blocks, there is not some magic boost number you need to stay under. Stay under 500 whp, and keep the a/f in check and you won't have any problems.

 

That's now what I'm saying at all let say I put a small turbo that would need to boost 18psi on to make that power do you think the stock block with stock compression and stock headgasket can handle that all day long?

I'm simple looking for something that won't require me to open the motor
Early on.

I'm not disagreeing with you at all but ten reason I ask is because I want this set up to be as low boost as possible to keep reliability high and cheaper than building an na.

If I can get 450whp with 5 psi then I would keep it that low. The question was intended to those who have similar setup just to give me an idea of what I need.

 

What I think your not getting is PSI does not determine total HP output. Also the turbo does not completely decide that you can run a lower boost and make the same HP. If your intake and heads are hogged out, that may be the case. But nobody is going to be able to tell you what PSI makes what HP. Timing, gas, abient air temp, intercooler vs non intercooled. Do you get what we are trying to say?

The only way to see what safe number your running is to slap it up on a dyno and test it. Or take a shot in the dark and hope it works.

 

18psi is no harder on the motor than 5psi if they both are making 500hp. Unless the tune is off.

 

Okay I understand what you mean. I just thought there was a way to calculate it.

But if anybody have similar setup they might chime in

 

Would the stock headgasket hold at 18psi? At 25? All day everyday?

Maybe wording things the wrong way.

What I'm saying is that im more concern about the reliability so If I'm boosting at 8psi with a big turbo wouldn't I have a smaller chance of blowing my headgasket than if I'm boosting 18psi on a tiny turbo under thesame power level?

Wouldn't you agree that on higher boost you have more chance of detonation on pump gas?

Well atleast that's what I think. Perhaps I'm wrong or misunderstood how thing work.(not being sarcastic here)

 

Well remember that boost is measure before the intake valve. So that 18 psi you see, is not what the combustion chamber sees.

The pressure difference to make the same hp on a stock setup is not going to vary that much. More like the big turbo might make it at 6-8 and the smaller turbo might make it at 10-12. Long as your intercooler can keep up it won't matter.

 

A agree with you, a larger turbo with lower pre turbine pressure. There are a lot of people thought that assume that they have to stay under som magic boost number though to keep the block together. This is simply untrue. Hopefully someone with a similar setup can chime in with what to expect.

 

Huh now I'm confused LOL

So okay so it doesn't see that 18 psi on the combust. Chamber. But would it be safe to assume that the higher the pressure(same turbo) the more unreliable(lack of a better word) it will be? Because more air + fuel= bigger bang so the headgasket might become an issues?

Am I on the right track or lost? LOL

 

I thought 20psi on 91 octain was the limit to not risk getting detonation.
Is this true?

I know if you can keep detonation away(meth or higher octain) you'll be fine.

I personally have run 22 psi on 91 octain on my supra and dicided to tune it down to 19psi to avoid that chance of detonation.
Do I have it wrong?

 

That might have been the case with Ãour supra setup, but every setup is diffrent. The knock threshold is going to change with different variables. A different sized turbo could take more or less boost before knock on pump gas then a smaller turbo. The mustang engine is a lot different than a supra motor.

 

Okay I think this is where I got it wrong. While I understand that each setup is different and the motor is different I thought is was a general thing that the limit of 91octain is around 20psi.

Thanks for clarifying that.